1. Field
Non-limiting example embodiments of the present invention relate to a liquid crystal display (LCD), and more particularly, to an LCD which is an electric device of changing various types of electrical information generated from various devices into visual information through a change in transmittance of liquid crystals by applying a voltage thereto, and displaying the visual information.
2. Description of the Related Art
In general, a liquid crystal display (LCD) is a display that displays images by controlling transmittance of light incident from a light source, using the optical anisotropy of liquid crystal molecules and the polarization property of a polarizing plate. Because of light, thin, high-resolution and large-size characteristics of LCDs, their application fields have been rapidly extended.
However, since images are displayed by transmitting light only to the light transmission axis of liquid crystal molecules, such LCDs have a narrower viewing angle that those of other displays.
Therefore, various technologies for improving the viewing angle have been developed such as, a patterned vertical alignment (PVA) mode. In the PVA mode, liquid crystal molecules are aligned vertically to upper and lower substrates, and cut-away patterns are formed at a pixel electrode and a common electrode opposite to the pixel electrode, respectively. Therefore, a plurality of multi domains are formed by distorting the electric field formed between the two electrodes.
However, like the PVA mode LCD, a vertical alignment type LCD has lower side visibility than front visibility. For example, in a PVA mode LCD having cut-away portions, a gamma characteristic is seriously distorted as viewed further away from the center to the front side, and in the worst case, the difference in luminance between high grayscales disappears. Therefore, the image may get distorted.
To solve such a problem, a method has been proposed in which, one pixel is divided into two sub-pixels, and a total storage capacitance is graded so that a high voltage is applied to a sub-pixel having a large storage capacitance and a low voltage is applied to a sub-pixel having a small storage capacitance, resulting in different transmittances.
However, when this method of dividing one unit pixel into two sub-pixels is applied to a high-resolution (e.g., 250 PPI or higher) LCD, the aperture ratio of the LCD is considerably lowered. Therefore, it is difficult to practically apply the method to the high resolution LCD.